Description: The Morphology/Pathology Core (MPC) has now been in existence for the past five years. The purpose of this core since its inception is to provide basic morphological services, consultation in experimental plans related to morphology and pathology, basic morphological services and assistance in the interpretation of experimental results. Services provided include assistance in obtaining human brain specimens, gross dissections, routine and special nervous system histology staining. Highly specialized staining techniques are also offered, including immunostaining, histochemistry, in situ hybridization, and quantitative autoradiography. Over these past five years, the number of investigators utilizing this facility are not quite the numbers anticipated in the original application. In spite of this, there has been a relatively constant utilization, from a low of five to a high of seven investigators each with multiple supported grants utilize this core facility. Since the inception of this core an impressive number of research slides have been processed. In an attempt to not overutilize the technical staff of this core and to avoid prolonged processing delays, over 21 research technologists, fellows, or students from laboratories utilizing this core have been trained in the various aspects of tissue preparation, sectioning and staining. Individual training time was from one hour to 57.5 hours. Activities taught included prepare tissue for cryostat sectioning, use of routine laboratory microtome, stain slides, and finally thin section tissues and examine by electronmicroscopy. This is excellent training for new investigators, students, and fellows.